Most DDR2-800 is programmed as DDR2-533 or DDR2-667. Same goes for faster varieties. This stuff is all overclocked at it's brand-rated speed, and requires manual configuration anyway.
There's a "new technology" that can make the nonstandard adjustments for you, called EPP or SLI-Memory. It's only an extended value, added to SPD, that tells the motherboard what voltage is needed to overclock the memory to a certain speed.